Variation in colony geometry modulates internal light levels in branching corals, Acropora humilis and Stylophora pistillata

Kaniewska, P., Anthony, K.R.N. and Hoegh-Guldberg, O. (2008) Variation in colony geometry modulates internal light levels in branching corals, Acropora humilis and Stylophora pistillata. Marine Biology, 155 6: 649-660. doi:10.1007/s00227-008-1061-5


Author Kaniewska, P.
Anthony, K.R.N.
Hoegh-Guldberg, O.
Title Variation in colony geometry modulates internal light levels in branching corals, Acropora humilis and Stylophora pistillata
Formatted title
 Variation in colony geometry modulates internal light levels in branching corals, Acropora humilis and Stylophora pistillata
Journal name Marine Biology   Check publisher's open access policy
ISSN 0025-3162
Publication date 2008-11-01
Year available 2008
Sub-type Article (original research)
DOI 10.1007/s00227-008-1061-5
Open Access Status
Volume 155
Issue 6
Start page 649
End page 660
Total pages 12
Place of publication Germany
Publisher Springer
Language eng
Subject C1
960808 Marine Flora, Fauna and Biodiversity
060205 Marine and Estuarine Ecology (incl. Marine Ichthyology)
Abstract Colonial photosynthetic marine organisms often exhibit morphological phenotypic plasticity. Where such plasticity leads to an improved balance between rates of photosynthesis and maintenance costs, it is likely to have adaptive significance. To explore whether such phenotypic plasticity leads to more favourable within-colony irradiance for reef-building branching corals, this relationship was investigated for two coral species Acropora humilis and Stylophora pistillata, along a depth gradient representing light habitats ranging from 500 to 25 mu mol photons m(-2) s(-1), during 2006 at Heron Island, Great Barrier Reef (23.44 degrees S, 151.91 degrees E). In the present study changes in flow- modulated mass transfer co-varied with light as a function of depth. In low-light (deep) habitats, branch spacing (colony openness) in A. humilis and S. pistillata was 40-50% greater than for conspecifics in high-light environments. Also, branches of A. humilis in deep water were 40-60% shorter than in shallow water. Phenotypic changes in these two variables lead to steeper within-colony light attenuation resulting in 38% higher mean internal irradiance (at the tissue surface) in deep colonies compared to shallow colonies. The pattern of branch spacing was similar for S. pistillata, but this species displayed an alternate strategy with respect to branch length: shade adapted deep and cave colonies developed longer and thinner branches, allowing access to higher mass transfer and irradiance. Corals in cave habitats allowed 20% more irradiance compared to colonies found in the deep, and had a 47% greater proportion of irradiance compared to colonies in the shallow high-light environment. Such phenotypic regulation of internal light levels on branch surfaces partly explains the broad light niches of many branching coral species.
Keyword Marine & Freshwater Biology
Marine & Freshwater Biology
MARINE & FRESHWATER BIOLOGY
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: 2009 Higher Education Research Data Collection
Centre for Marine Studies Publications
 
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Citation counts: TR Web of Science Citation Count  Cited 25 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 28 times in Scopus Article | Citations
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Created: Wed, 15 Apr 2009, 23:52:11 EST by Peter Fogarty on behalf of Centre for Marine Studies